I think there's been an upswing in the popularity of the revolver for the past few years, but I'm not sure I'd go so far as to identify it as a "comeback."

S&W and Ruger have been coming out with new models or variations (Ruger probably moreso than S&W), aside from their 642/442/640 and LCR, respectively, models being popular. Colt has been bringing back some of their revolvers. Kimber has been having success with their revolvers. I think RIA has a revolver or two out, as well.

At the same time, I'd imagine that semi-auto sales, especially polymer guns, far outpace revolver sales. I don't have the numbers, so I could be wrong, but I doubt it.

Just my opinion.